Speedup applications boot by caching require calls
Speedup applications boot by caching file locations during require calls.
Speed gain depends on your number of gems. Under 100 gems you likely won’t see the difference,
but for bigger applications it can save 1 to 3 seconds of boot time per 100 used gems.
# Gemfile
gem 'bootscale', require: false
For correctness cache should be updated everytime $LOAD_PATH
is modified by calling Bootscale.regenerate
.
For Rails apps it means adding an initializer in config/application.rb
.
module MyApp
class Application < Rails::Application
initializer :regenerate_require_cache, before: :load_environment_config do
Bootscale.regenerate
end
end
end
Locate require 'bundler/setup'
in config/boot.rb
and add require 'bootscale/rails'
after it:
require 'bundler/setup'
require 'bootscale/rails'
Locate require 'bundler/setup'
, and add require 'bootscale/setup'
after it:
require 'bundler/setup'
require 'bootscale/setup'
In order to gain ~10-30ms of extra load speed, you can use the msgpack gem:
# Gemfile
gem 'msgpack', require: false
gem 'bootscale', require: false
# config/boot.rb (or wherever you have the require of bundler/setup)
require 'bundler/setup'
require 'msgpack'
require 'bootscale/setup' # or require 'bootscale/rails'
Bootscale caches the absolute location of all requirable files on the $LOAD_PATH and
patches require
+ autoload
to use these absolute paths, thereby avoiding having to check all load paths for every require.
Problem outlined in this talk
If you’re experiencing problems with loading your application, especially after moving files around, try deleting the tmp/bootscale
folder.
Bug reports and pull requests are welcome on GitHub at https://github.com/byroot/bootscale.
Local development: your load time will be very slow when using a local copy for development like gem 'bootscale', path: '~/Code/bootscal'
, use via git instead.
Thanks to Aaron Patterson for the idea of converting relative paths to absolute paths.